Transverse-longitudinal sequential discharge excitation of high-pressure laser

Abstract

An electrically excited gas laser having a dual-purpose electrode configuration. Two long parallel metal electrodes on opposite sides of the gas volume are almost totally enclosed in a dielectric body material. A raised projection of each electrode, at opposite body ends, is in direct contact with the laser gas. A conventional pulse generator is connected to the electrodes. When a pump pulse is applied, a transverse glow discharge is initiated which rapidly gives way to a main longitudinal discharge. In an alternate arrangement, the electrodes comprise several discharge sections in series along the laser body, connected in electrical parallel to the pulse generator.

What is claimed is: 
     
       1. An electric discharge excited gas laser comprising a gas volume defined by a dielectric body having an elongated open central space, beam-forming reflector means mounted on said body at respective ends of said volume, an elongated cathode electrode and an elongated anode electrode in said body substantially parallel to each other on opposite sides of said gas volume, each said electrode having a projection portion extending from one end thereof toward the opposite side of said gas volume, said projections being at opposite respective longitudinal ends of said gas volume, and said electrodes being embedded in said dielectric body except for having said projections, only, exposed directly to said gas volume, said electrodes forming a transverse predischarge path between the major, embedded, portions of their lengths and a longitudinal main discharge path between said projections. 
     
     
       2. Apparatus in accordance with claim 1 wherein said projections are raised integral portions of said electrodes. 
     
     
       3. Apparatus in accordance with claim 1 wherein said projections extend the full width of their respective electrodes transversely of said gas volume. 
     
     
       4. Apparatus in accordance with claim 1 including high-voltage pulse generating means, and means electrically connecting said pulse generating means across said electrodes. 
     
     
       5. Apparatus in accordance with claim 1 wherein each of said electrodes is left short at the end opposite the said projection on the other electrode, so that there is no electrode material directly opposite either of said projections. 
     
     
       6. Means for sequentially electrically exciting a gas laser, comprising a pair of extended electrodes on opposite sides of the gas cavity in said laser, means for initiating a transverse electric discharge between said electrodes, and means for establishing a longitudinal electric discharge between longitudinally opposite end portions, only, of said electrodes when the gas in said cavity has become ionized by said transverse discharge, said longitudinal discharge-establishing means including a raised projection at one respectively opposite end of each said electrode, said projections extending respectively from said electrodes toward the opposite side of said cavity. 
     
     
       7. Apparatus in accordance with claim 6 wherein said electrodes are enclosed in a dielectric material, and including means defining an opening in said dielectric material around each said projection, whereby said projections are directly exposed to said gas cavity. 
     
     
       8. Apparatus in accordance with claim 6 wherein said discharge means include means for supplying a single high-voltage pulse across said pair of electrodes. 
     
     
       9. Apparatus in accordance with claim 6 wherein said electrodes are enclosed in a dielectric material, including means defining an opening in said dielectric material around each said projection directly exposing said projections to said gas cavity, and wherein said discharge means include means for supplying a single high-voltage pulse across said pair of electrodes.